Association of Insect-Derived Ear Injury With Yield and Aflatoxin of Maize Hybrids Varying in Bt Transgenes

2019 ◽  
Vol 48 (6) ◽  
pp. 1401-1411 ◽  
Author(s):  
Luke S Pruter ◽  
Michael J Brewer ◽  
Mark A Weaver ◽  
Seth C Murray ◽  
Thomas S Isakeit ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Integrated Approach ◽  
Corn Earworm ◽  
Data Sets ◽  
Maize Production ◽  
Maize Hybrids ◽  
Corpus Christi ◽  
Bt Protein ◽  
Ear Injury

Abstract Environmental factors have been associated with the production of aflatoxin in maize, Zea mays L., and it is inconclusive whether transgenic, Bacillus thuringiensis (Bt), maize has an impact on aflatoxin accumulation. Maize hybrids differing in transgenes were planted in two locations from 2014 to 2017. Yield, aflatoxin, and ear injury caused by corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), were measured across three groups of hybrids differing in transgenes including near-isogenic hybrids, and water-stressed conditions. The hybrid groups consisted of non-Bt hybrids with no Bt transgenes, a second group with one or more Cry-Bt transgenes, and the third group with vegetative insecticidal Bt protein and Cry-Bt transgenes (Cry/Vip-Bt). Across the six data sets derived from 11 experiments, the Cry-Bt and Cry/Vip-Bt hybrids had less ear injury and aflatoxin on average than non-Bt hybrids. The effects of ear injury on yield and aflatoxin were more prominent and consistent in Corpus Christi, TX, where hybrids experienced more water-limited conditions than in College Station, TX. The trend of increased aflatoxin among hybrids with increased ear injury was further resolved when looking at Cry-Bt and Cry/Vip-Bt isogenic hybrids in Corpus Christi. The results supported that the maize hybrids with the inclusion of Cry-Bt and Cry/Vip-Bt transgenes warrant further investigation in an integrated approach to insect and aflatoxin management in sub-tropical rain-fed maize production regions. Research outcomes may be improved by focusing on areas prone to water-stress and by using hybrids with similar genetic backgrounds.

Behavioral Interactions Between the Hyperparasitoid Mesochorus discitergus (Hymenoptera: Ichneumonidae) and Four Species of Noctuid Caterpillars: Evasive Tactics and Capture Efficiency

1994 ◽  
Vol 29 (3) ◽  
pp. 420-427 ◽  
Author(s):  
M. E. Baur ◽  
K. V. Yeargan
Keyword(s):  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Fourth Instar ◽  
Capture Efficiency ◽  
Behavioral Interactions ◽  
Lepidopteran Larvae ◽  
Noctuid Species ◽  
Soybean Looper

The hyperparasitoid, Mesochorus discitergus (Say), oviposits into larvae of primary parasitoids while the latter are developing inside various lepidopteran hosts. To accomplish hyperparasitism, M. discitergus must capture the lepidopteran larvae. We studied the evasive behaviors of 2nd-, 3rd-, and 4th instar Helicoverpa zea (Boddie) (corn earworm), Pseudoplusia includens (Walker) (soybean looper), Spodoptera frugiperda (J. E. Smith) (fall armyworm), and 2nd- and 4th-instar Plathypena scabra (Fabricius) (green cloverworm), as well as the effectiveness of these tactics in eluding capture by M. discitergus females. Most individuals of all instars of corn earworm and fall armyworm made minimal efforts to escape. Although not commonly used by corn earworm and fall armyworm, their occasional vigorous responses were effective in deterring M. discitergus females. Dropping from a leaf, either unattached or attached by a thread, was also effective for preventing capture of those two noctuid species. Soybean loopers and green cloverworms responded much more actively. Second-instars of both species dropped off the leaf on a thread, while 3rd- and 4th-instar soybean loopers commonly used vigorous responses. Fourth-instar green cloverworms used vigorous responses and dropping off the leaf. Overall, 68% of the caterpillars using the vigorous response were captured, while 39% of those dropping on a thread and about 26% of those dropping off a leaf, unattached by a thread, were captured. Green cloverworms and soybean loopers were more difficult to capture than corn earworms and fall armyworms.

Ear Pests and Damage to Organic, Conventional and Bt-Protected Sweet Corn Grown in Central Kentucky

2009 ◽  
Vol 44 (4) ◽  
pp. 383-390
Author(s):  
John D. Sedlacek ◽  
Karen L. Friley ◽  
Steve L. Hillman
Keyword(s):  
Helicoverpa Zea ◽  
European Corn Borer ◽  
Sweet Corn ◽  
Crop Protection ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Genetically Engineered ◽  
Corn Borer ◽  
Sap Beetles ◽  
Southwestern Corn Borer

Sweet corn (Zea mays L. var. rugosa) was grown in replicated plots in 2004 and 2006 using organic, conventional, and genetically-engineered (Bt) production practices. Organic plots were treated with Entrust® (Dow AgroSciences LLC, Indianapolis, IN) whereas conventional and Bt sweet corn plots were treated with Warrior® (Syngenta Crop Protection, Inc., Greensboro, NC). All plots were treated once at silk emergence. Organic and conventional plots were treated again 1 wk later. Twenty-five ears were harvested from row centers in each treatment subplot to quantify ear pests and assess ear damage. The highest number of corn earworm, Helicoverpa zea (Boddie), larvae were found on organically-grown sweet corn. European corn borer, Ostrinia nubilalis (Hübner); southwestern corn borer, Diatraea grandiosella Dyar; and fall armyworm, Spodoptera frugiperda (J.E. Smith), larvae were not found as frequently. Neither corn earworm nor European corn borer larvae were found on Bt sweet corn ears. Sap beetles, Carpophilus lugubris Murray, were found on all 3 types of sweet corn. Organically and conventionally-grown sweet corn had a greater number of tip-damaged ears and numbers of damaged kernels per ear than Bt sweet corn. Ear length and weight were the same for all 3 types of sweet corn. Based on the information generated in this study, growing late-planted sweet corn organically or conventionally on a large commercial scale with a limited spray program and without using other types of ear pest management does not appear to be a practical or profitable option in central Kentucky.

INFESTAÇÃO DE MILHO CRIOULO, CONVENCIONAL E TRANSGÊNICO PELA LAGARTA-DO-CARTUCHO E PELA LAGARTA-DA-ESPIGA E PARASITISMO DE OVOS

2017 ◽  
Vol 16 (3) ◽  
pp. 351
Author(s):  
CAMILA CORRÊA VARGAS ◽  
ROSANA MATOS DE MORAIS ◽  
LUIZA RODRIGUES REDAELLI
Keyword(s):  
Zea Mays ◽  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Genetically Modified ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Trichogramma Pretiosum ◽  
Hybrid Corn ◽  
Egg Parasitism ◽  
Santa Maria

RESUMO - O objetivo foi avaliar a infestação, o parasitismo de ovos e danos da lagarta-do-cartucho, Spodoptera frugiperda (J. E. Smith), e da lagarta-da-espiga, Helicoverpa zea (Boddie), em cultivares de milho: variedade crioulo (Lombo Baio), híbrido convencional (Semilha S395) e híbrido geneticamente modificado (Bt) (TC1507 Herculex I ®, Cry1F). O experimento foi conduzido em Santa Maria-RS, no período de segunda safra de 2014. O delineamento foi de blocos ao acaso, com três tratamentos e quatro repetições. Foram registrados os danos, o número de lagartas, de posturas e o parasitismo em ovos da lagarta-do-cartucho, dos 9 aos 72 dias após a emergência das plantas (DAE). A infestação da lagarta-da-espiga e o parasitismo de ovos foram registrados dos 67 aos 101 DAE. Os danos causados pela lagarta-do-cartucho foram semelhantes entre milho crioulo e convencional, os quais foram mais elevados do que no milho geneticamente modificado Bt. O número médio de lagartas-do-cartucho foi maior em milho crioulo. A média do número total de lagartas-da-espiga foi semelhante entre milho crioulo e convencional e superior à do Bt. Foi registrado o parasitismo de ovos para a lagarta-da-espiga por Trichogramma pretiosum Riley, nas três cultivares avaliadas, com porcentagens semelhantes entre milho crioulo e convencional e superior em milho Bt. Palavras-chave: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, manejo de pragas. INFESTATION IN INLANDRACE, CONVENTIONAL AND TRANSGENIC CORN BY FALL ARMYWORM AND CORN EARWORM, AND EGG PARASITISM  ABSTRACT - The objective of the work was to estimate the infestation and eggs parasitism of fall armyworm (J. E. Smith) and corn earworm (Boddie), in three corn varieties: landrace (LomboBaio), conventional hybrid (Semilha S395) and genetically modified hybrid (Bt) (TC1507 Herculex I ®, Cry1F). The experiment was carried out in Santa Maria-RS, during the second-season corn crop, in 2014. The experimental design was a completely randomized block with three treatments, and four replicates. We evaluated the damages, number of larvae, number of eggs and fall armyworm egg parasitism from 9 to 72 days after emergence (DAE). The infestation of corn earworm and the eggs parasitism were measured from 67 to 101 DAE. Fall armyworm damage was similar between landrace and conventional hybrid, and both higher than those of genetically modified hybrid Bt. Average number of fall armyworm larvae was higher in landrace cultivar. The average of total number of corn earworm larvae was similar on landrace and conventional hybrid, both higher than Bt hybrid. Corn earworm eggs parasitism by Trichogramma pretiosum Riley was recorded in the three evaluated cultivars and similar parasitism percentage was observed between landrace and conventional hybrid, which was higher in Bt maize. Keywords: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, pest management.

scholarly journals ACTION SPECTRUM OF Baculovirus spodoptera ON LEPIDOPTERA PESTS

2017 ◽  
Vol 16 (1) ◽  
pp. 52
Author(s):  
CAMILA DA SILVA FERNANDES SOUZA ◽  
FERNANDO HERCOS VALICENTE ◽  
MARCOS ANTÔNIO MATIELLO FADINI ◽  
RICARDO ANTÔNIO POLANCZYK
Keyword(s):  
Spodoptera Frugiperda ◽  
Sugar Cane ◽  
Helicoverpa Zea ◽  
First Generation ◽  
Action Spectrum ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Corn Borer ◽  
Egg Masses ◽  
Diatraea Saccharalis

ABSTRACT - This work evaluated the spectrum of action of Baculovirus spodoptera (SfMNVP) - 6NR on the fall armyworm Spodoptera frugiperda, corn earworm Helicoverpa zea and the sugar cane borer Diatraea saccharalis, species of economic importance in maize. For the bioassays, corn leaves immersed in a baculovirus suspension were used for baculovirus inoculation in fall armyworm and earworm and pieces of sugar cane for the corn borer. The foods were immersed in viral solutions of different baculovirus concentrations determined in a Neubauer chamber. The control only distilled water was used instead of the baculovirus suspension. The larvae fed for 48 hours and were then transferred to an artificial diet, without the baculovirus. After evaluating mortality, the development of the offspring (F1) was accompanied, evaluating the parameters: mortality, pupation and the number of egg masses in the first generation. The baculovirus was specific to fall armyworm and innocuous to earworm and the corn borer in the first generation. In the second generation, baculovirus was innocuous for all three species. The percentage of pupation showed an inverse relation with mortality for the three species in two generations. The number of egg masses in F1 was lower in S. frugiperda, did not change for D. saccharalis and higher in H. zea.Keywords: Helicoverpa zea, Spodoptera frugiperda, Diatraea saccharalis, entomopathogenie virus.ESPECTRO DE AÇÃO DE Baculovirus spodoptera A LEPIDÓPTEROS PRAGARESUMO - Neste trabalho foi avaliado o espectro de ação do Baculovirus spodoptera (SfMNVP) - 6NR à lagarta-do-cartucho Spodoptera frugiperda, à lagarta-da-espiga Helicoverpa zea e à broca-da-milho Diatraea saccharalis, espécies de importância econômica na cultura do milho. Para a realização dos bioensaios foram utilizadas folhas de milho imersas em suspensão com o baculovírus em concentrações determinadas em câmara de Neubauer, para lagarta-do-cartucho e para lagarta-da-espiga. Para broca-do-milho o substrato utilizado foi colmo de cana-de-açúcar. Na testemunha foi utilizada somente água destilada ao invés da suspensão com o baculovírus. As lagartas se alimentaram por 48 horas, após este período, foram transferidas para dieta artificial sem o bacilovírus. Após a avaliação da mortalidade,odesenvolvimento da prole (F1) foi acompanhado sendo avaliados os parâmetros: mortalidade, pupação e o número de massas de ovos na primeira geração. O baculovírus foi especifico para lagarta-do-cartucho e inócuo tanto para lagarta-da-espiga quanto para broca-do-milho na primeira geração. Na segunda geração, o baculovírus foi inócuo para as três espécies. A porcentagem de pupação apresentou relação inversa com a mortalidade para as três espécies nas duas gerações. O número de massas de ovos na F1 foi menor em S. frugiperda, não alterado para D. saccharalis e maior em H. zea.Palavras-chave: Helicoverpa zea, Spodoptera frugiperda, Diatraea saccharalis, vírus entomopatogênico.

Compatibility of Nuclear Polyhedrosis Viruses and Inherited Sterility for Control of Corn Earworm and Fall Armyworm (Lepidoptera: Noctuidae)

1997 ◽  
Vol 32 (2) ◽  
pp. 148-153 ◽  
Author(s):  
J. J. Hamm ◽  
J. E. Carpenter
Keyword(s):  
Helicoverpa Zea ◽  
Nuclear Polyhedrosis Virus ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Management Approach ◽  
Significant Difference ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
Lepidoptera Noctuidae ◽  
Inherited Sterility

Inherited sterility has been proposed as a means of suppressing the populations of the corn earworm, Helicoverpa zea (Boddie), and the fall armyworm, Spodoptera frugiperda (J. E. Smith). If nuclear polyhedrosis viruses could be used to kill larvae, thereby reducing the number of moths in the field populations, fewer moths treated with substerilizing doses of irradiation would need to be released. However, for these two methods to be compatible, the progeny of substerile moths should be no more susceptible to the virus than the progeny of the field populations. The corn earworm nuclear polyhedrosis virus (Elcar™) was bioassayed against corn earworm larvae from untreated moths and larvae from male, female, and male and female moths treated with 100 Gy of irradiation and larvae from male moths treated with 150 Gy of irradiation. The fall armyworm nuclear polyhedrosis virus was bioassayed against fall armyworm larvae from untreated moths and larvae from male moths treated with 100 to 150 Gy of irradiation. There was no significant difference between susceptibility of larvae from untreated moths and larvae from irradiated moths. Thus, the use of nuclear polyhedrosis viruses for control of larvae should be compatible with the release of substerilized moths as part of an integrated pest management approach for area-wide management of the corn earworm and fall armyworm.

Bionomics of the Fall Armyworm (Lepidoptera: Noctuidae) and Its Ectoparasitic Nematode, Noctuidonema guyanense, in South Georgia

1996 ◽  
Vol 31 (2) ◽  
pp. 209-217
Author(s):  
C. E. Rogers ◽  
O. G. Marti ◽  
L. D. Chandler ◽  
A. M. Simmons
Keyword(s):  
Spodoptera Frugiperda ◽  
Heliothis Virescens ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Cotton Bollworm ◽  
Tobacco Budworm ◽  
Beet Armyworm ◽  
South Georgia ◽  
Lepidoptera Noctuidae

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a perennial immigrant pest of several crops in south Georgia. Moths of S. frugiperda commonly are infested by an ectoparasitic nematode, Noctuidonema guyanense Remillet and Silvain in the Southeast. The seasonal chronology and natural association of these species are reported for Tift Co. from 1988 to 1994. Seasonal influxes of non-infested moths usually arrive in late April and dissipate in early November. Seasonal influxes of infested male moths follow the initial immigrants by 4 to 6 wks and disappear in the fall from 1 to 2 mos earlier than the general moth populations. Feral male moths that are moderately worn and infested by N. guyanense weigh less than moderately worn, non-infested males. Noctuidonema guyanense infests moths of several species of noctuids, but it has not been found on the cotton bollworm/corn earworm [Helicoverpa zea (Boddie)], tobacco budworm [Heliothis virescens (Fab.)], or beet armyworm [S. exigua (Hubner)].

Survival of Archytas marmoratus (Diptera: Tachinidae) in Helicoverpa zea and Spodoptera frugiperda (Lepidoptera: Noctuidae) at Low Temperatures and Short Days

2000 ◽  
Vol 35 (1) ◽  
pp. 9-21 ◽  
Author(s):  
F. I. Proshold ◽  
J. E. Carpenter
Keyword(s):  
Spodoptera Frugiperda ◽  
Low Temperatures ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Host Population ◽  
Corn Earworm ◽  
Diapause Induction ◽  
Threshold Temperature ◽  
Lepidoptera Noctuidae ◽  
Short Days

Archytas marmoratus (Townsend) was reared on corn earworm, Helicoverpa zea (Boddie), or fall armyworm, Spodoptera frugiperda (J. E. Smith). Rearing chambers were programmed for a constant temperature of 15, 16, 19, 20, 22, 24, or 25°C and a photoperiod of 10:14 h (L:D) or 25°C and a photoperiod of 12:12 h (L:D). Development of parasitoids was faster when corn earworm larvae were parasitized than when fall armyworm larvae were parasitized. At 15°C parasitoid survival was poor on both hosts but at 16°C, more parasitoids eclosed on corn earworm than fall armyworm. Diapause induction in this strain of corn earworm was low. All pupae that eclosed after being in diapause produced an adult corn earworm. The data suggested that A. marmoratus is not influenced by diapause induction in its host but continues to develop above the threshold temperature for survival. This would restrict its overwintering as a larva or pupa to regions that have a continuous, nondiapausing host population. Thus, yearly establishment of A. marmoratus in more temperate areas would be required.

Peanut Fungicides: Effect on Survival and Development of the Corn Earworm, Fall Armyworm, and Velvetbean Caterpillar1

1996 ◽  
Vol 23 (2) ◽  
pp. 116-123 ◽  
Author(s):  
Robert E. Lynch
Keyword(s):  
Spodoptera Frugiperda ◽  
Helicoverpa Zea ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Anticarsia Gemmatalis ◽  
Velvetbean Caterpillar ◽  
Survival And Development ◽  
Comparable Concentration ◽  
Terminal Buds ◽  
Army Worm

Abstract The fungicides chlorothalonil, tebuconazole, and propiconazole commonly used for control of peanut diseases were evaluated for activity against the corn earworm [Helicoverpa zea (Boddie)], fall armyworm [Spodoptera frugiperda (J. E. Smith)], and velvetbean caterpillar (Anticarsia gemmatalis Hübner). Chlorothalonil most adversely affected early establishment and survival of neonates of all three insect species on peanut terminal buds. Chlorothalonil also decreased the weight of larvae of all three species at 10 d and extended the time to pupation for fall armyworm and velvetbean caterpillar larvae. Similarly, tebuconazole adversely affected early survival and establishment, decreased 10-d weight and extended time to pupation of corn earworm and velvetbean caterpillar larvae, but had little effect on fall armyworm larvae. Propiconazole had no effect on establishment and survival of corn earworm and fall armyworm larvae on peanut terminals, and actually increased the weight of 10-d-old larvae for all three insects over that recorded for the untreated control. Orthogonal comparisons of the activity of five chlorothalonil-based fungicides against the fall army-worm showed that the activity was due to chlorothalonil rather than to formulation. At equivalent concentrations used in the field, Bravo Ultrex® was significantly more active against larvae of the fall armyworm than was a comparable concentration of Bravo 72®. However, regression lines did not differ for the two fungicides for any of the developmental parameters measured when larvae of all three species were fed different concentrations of Bravo 720® and Bravo Ultrex® in their meridic diet.

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